Automatic feed caulking gun



Dec. 2, 1958 R. G. AMES AUTOMATIC FEED CAULKING cum 3 Sheets-Sheet 1 Filed Aug. 21, 1956 :El I3; 8.

I NVENTOR ROBERT 6- AMES AT TORNEYS Dec. 2, 1958 R. G.,AMES

AUTOMATIC FEED CAULKING GUN 3 Sheets-Sheet 2 Filed 'Aug. 21, 1956 F EE 9 7 33 w 3 5 w R E o M m 1 H v v T m M M 3 ..a I E M I B I o a a a R Y /..,H. a a I A 2 3 6 1. 2 ill, 6 a2 6 B D 5 m 1 H W 1% 5 l 2 2.|l...| 2 7/) J 6 4: a M M 6 2 2 2 Q 6 ATTORNEYS Dec 2, 1958 Filed Aug. 21, 1956 R. G. AMES V 2,862,382

AUTOMATIC FEED CAULKING GUN 3 Sheets-Sheet 3 nan- I N VE N TOR Ro BE R T G AMEs BY ,a. a a

A 'r TOR H E vs 2,862,382 AUTOMATIC FEED CAULKING GUN Robert G. Ames, Hillsborough, Califl, assignor of onefourth to Stanley Ame s, one-sixth to Katherine A. Williams, one-sixth to Lois W. Rosebrook, and onesixth to George W. Williams HI, Hillsborough, Calif.

Application August 21, 1956, Serial No. 605,250 9 Claims. 01. 72-130 The present invention relates to improvements in an automatic feed caulking gun. It consists of the combinations, constructions and arrangement of parts, as hereinafter described.

In my copending application on a Self-Contained Dry Wall Taper, Serial No. 454,563, filed in the United States Patent Ofiice on September 7, 1954, now Patent No. 2,815,142, there is disclosed a tool having a hollow handle, which is adapted for holding a supply of mastic. As shown therein, the tool is designed for extruding the mastic over a seam defined by wall boards, and simultaneously applying a strip of tape over the mastic.

Although certain structural features of the above-identified copending application are carried forward into the present disclosure, the caulking gun herein shown is designed'for applying a ribbon of mastic to a stud, joist or other building member. Such a mastic, which has a rubber base, may be utilized for securing a wall board to the stud, joist or the like, without requiring the use of nails. However, the tool is not limited to the use of rubber base mastics. Moreover, the caulking gun may be employed for filling a groove in a building structure.

Briefly stated, the present automatic feed caulking gun includes a tubular handle having a bore adapted to contain a supply of mastic. The gun is provided with a mastic-delivering nozzle arranged at one end of the handie, and this masticis forced through a conduit from the handle to the nozzle by means of a piston. The latter is advanced along the bore of the handle by a cable, which is wound upon a drum, as the tool is advanced along the stud, joist or other building member.

This drum is turned by a traction wheel and a drive mechanism. Experience has shown that operators are prone to force the traction wheel, when an insufiicient amount 'of mastic is being delivered from the nozzle; and this may result in breaking the cable, as the piston reaches the forward end of its stroke.

Accordingly, and as one of the cardinal objects of this invention, it is proposed to automatically disengage the drive mechanism from the drum, as the piston completes its forward stroke, thus precluding the breaking of the cable.

Broadly speaking, the caulking gun is advanced'along the building member, as the mastic is delivered thereto, and thus the handle is moved into various angular positions relative to the member to which the mastic is being applied. As another important object, therefore, I propose to provide a mastic-delivering nozzle that is designed to maintain contact with the building member, 'as the handle moves through various angular positions. Asa still further object of the invention,.it is proposed to arrange a guide on the caulking gun, which will aid materially in assisting the operator in moving the gun along the stud, joist or other building member, when the mastic is being applied thereto.

Another object is to provide a valve,'which is automatically, opened as the mastic-delivering nozzle is being advanced, thevalve being closed again upon removing the caulking gun from the stud, joist or other member of the building. i

Other objectsand advantages will appear as the speciillustrated in section;

r 2,862,382 Patented Dec. 2, 1958 F KC 7 fication proceeds, and the novel features of the invention will be set forth in the claims appended hereunto.

Drawings Figure 3 is an elevational view of the caulking gun,'

disclosing it after being urged against a wall stud and being advanced therealong; V V

Figures 4 and 5 are transverse sectional views taken along the vertical planes IVIV and V--V, respectively, of'Figure 2;

Figure 6 is a side view of thecomplete caulking gun, on a reduced scale, with'part of Figure 7 'is a sectional view suggesting a wall board as being secured to studs, or joists, by ribbons of mastic;

Figure 8 is a fragmentary topplan view of my caulking gun, with an offset mastic-delivering nozzle arranged to fill a groove in a building'structure, which groove is aligned with the traction wheel to serve as a guide for the latter; and I 7 Figure 9 is a side elevational view of Figure 8, with the modified gun being advanced along the building structure. v

While I have shown only the preferred forms of my invention, it should be understood that various changes, or modifications, may be made within the scope of the annexed claims without departing from the spirit thereof.

Detailed description Referring now to Figures 1 to 6, inclusive,of the drawings, my'automatic feed caulking gunis designated generally at A. It includes a tubular handle B adapted to" board to studs or ceiling joists, without requiring the use" of nails.

to the use of rubber basemastics. r

As disclosed in the drawings, a mastic-delivering noz- As previously stated, the gun is not limited zle D is arranged adjacent to one end of the handle B; r and a mastic-feeding conduit E places the bore 10 of the handle in communicationjwith the nozzle, whereby mastic C may be transferredfrom the bore to the nozzle. Figure 4 clearly shows the interior'of the conduit E as communicating with the interior of the nozzle D. Thus themastic may flow from the conduit to the nozzle,-as

suggested by the arrow 10a in Figure 1. In actual practice, the conduit E is made in sections E and E which are removably secured together by screws 9 (see Figure 2').

With particular'reference to Figures 1, 2 and 6, it will be observed that a piston F is mounted in the bore 10 in back of the supply of mastic, the piston being movable. toward the nozzle D to advance mastic C to the latter. r

For the purpose of advancing the piston E, a drum 11 is rotatably mounted in the section E of the conduit E so as 'toextend transversely across the latter. As shown in Figures 1 and 5, one end of the cable 12 is anchored to the drum by a screw 13, or other. suitable fastening of Figure 1, with a A the tubular handle being and applying mastic to a 3. means, whichis disposed'adjacent to one end of the drum. The opposite end of the cable is securedto a nut 14', the latter being threaded upon a rod 15. With particular referenceto Figures 1 and 6, ,it will be noted that thisrod is anchoredto' the pistenF; and. is. provided with a guide disc 16 that is slid'a'bly disposediin the bore of the handle B. This arrangement prevents the piston from tilting,.but permits it to slide and rotate relative to the handleas the piston is pulled forwardly in the bore.

As illust'rated in Figure 1 a disc 17 is clampedto the piston F by the nut 14 and the rod 1 5, and is fashioned withv an. opening 18' through which therear end of the cable 12 passes. Thus the cable is guided to the-piston in offset relatiomwith respect to the piston axis, whereby the'pistonmay turn, as the, cable is wound on the drum 11 from one end of the latter toward its other end, as disclosedrin Figure l of the drawings. This will permit thec'ahleportionbetween the drum and the pistonto liev in a transversely moving plane thatextendssubstantially atright angles-to the drum axis at ,all times.

In order to forcethe masticvC throughathegconduitE and the nozzle D, a traction wheel G is provided. This.

wheel has itsperiphery; fashioned withteeth 19.. These teethvare engageable with a buildingmember H against which a ribbon 20 of the mastic C. may be. extruded (seer-Figure 3). As previously mentioned, this member maybe a stud, joist, or the'like, to; which awall board 21 is: to be attached by meansofgthemastic (see. Figure 7-) A- pawl;l9a:engages with theteeth' 19 so. as tonormally prevent reverse movement of the'traction wheel.

It will be-observed from. Figure 4 that. the. traction wheel G has its hub 22 secured to a transversely-extending arrow 28finrF-igure 3; the whe-el "will be-turned in the directionwof the: arrow 129; thus rotatingthe pinion 27. For. the. purpose of turning the drum 11', a drive mechanism- I f has been provided. Although a seriesofgea-rs' hasabeeni shown .in Figure 2" as consti'tutingthis' drive mechanism, it will be obvious that a chain and sprocket drive couldbe-substitutedtherefor. The mechanism] includes a driven gear 30; which-is disposedin*axial relation: with respecttothedrur'n*11 (see- Figures 1, 2 and'i5')i V 1 It is important that the drum 1-1 be automatically disengaged-from the-drive mechanism-=1, when the piston F approaches the forward end of its stroke. This will precluderthe'breaking of the cable 12upon further rotation-..of:the traction: wheel G; Experience has shown that an operatormay force: the-traction wheel along the member H when the mastic C stops flowing fromthenozzle D',E.CV6I1-thO11gh1 the: piston F has completed its stroke. This .isdue: to the fact that the piston is enclosed by the tubular'handle B and 1 cannot be observed=by. the operator; For this reason, an automatic clutch'K has been provided;

Reference is made to Figures 1, 2 and 5, wherein it willxbeseen'that the: drum 11 isrigidly connectedto a hollow shaft=311 bya set-screw 32. This shaft" has the web; 33 :of a channel-shaped bar 34 welded thereto, and

this'zbar'constitutes one element of the clutch K-.' A drive dog 35 is swingably attached by a pivot pin 36 tothe channels'bar 34; and carries a lckirig -detent 37 that projects;;throughianopening 38' form'ed' in the web 33. Moreover, a spring. 39' isan'chored'to this web and' yield inglyrurges thedetent 37 into any one of a series ofradialv-slots 40.!fashionedwinthegear 30 (see Figure 2),

When the locking detent is projected into one of the slots 40' by the spring 39, rotation of the gear 30' by the drive mechanism I will cause the drum 11 to turn, thereby pulling the piston F forwardly and thus extruding mastic C from the nozzle D. However, when the piston approaches the forward end of its stroke, it will engage with a clutch-operating rod 41 that is arranged' in the path of the advancing-piston (see Figure 1 As the piston continues to advance, the rod 41- will swing a bell-crank lever 42. The latter is provided with a depending finger 43, which is arranged to' move a; disc 44 toward the drum 11. This disc is fixed-to a spindle 45, which extends axially through the hollow shaft 31 so as to abut the drive dog 35. Accordingly, when the rod 41 ispushed forwardly by the piston F, the detent 37 will be disengaged from the driven. gear'30, at which time. the clutch K will be disengaged. carried by the conduit section B so as to limit the movement of the disc 44 away from this conduit.

The structural details of the mastic-delivering nozzle D is illustrated in Figures. 1 to 4, inclusive. It is mounted forswinging movement about the shaft 23, which coincides with the axis of the traction-wheel G. This nozzle has an outlet end provided witha; surface 47 arranged to abut the memberjH to which the ribbon 20 of mastic, is to-be applied. As sug-geste d by the dotdash line 48 in Figure 2, the surface 47 defines a plane arranged tangentially to the periphery of the traction wheel G. Thus the surface 47 of the swingable nozzle will maintain contactwith the member H, as the caulking gun A; is advanced'therealong, regardless of theangular relationof the-handle B with respect to this member.

In Figure 3,,a spring 49 has been illustrated as having one of. its ends attached by a pin 50 to the: masticdelivering nozzle D, while its: other end is secured to an eyelet'51 fixed to the conduitE. This; construction will yieldingly urge the nozzle to' apredeterminednormal position, as shown in Figure 2,,when1the caulking. gun is removed from the member. H; Atethis' time; the nozzlewill abut an adjustable screw 52, whichziscarried by abracket-53 fixed'to thezconduit1section:E

The nozzle D has an outlet opening; 542 fashioned therein, through: which the ribbon-.20 ,0f;mastic.'is=discharged .against the member; H. A;valve.55: is 1 disposed to control the outflow ofv the masticfrom. thenozzle, and this valve normally closes this opening; asidisclo'sed in Figure 2. However, a valveaactu'atingzdevice.I; is

operable to automatically open the: valve 55,.when the nozzle'is swung: in acountercloclcwise direction in Figure:2,1 and toclose the valve upon thel swinging ofthe nozzle in the opposite direction;

In its structural features the. valve actuating'device L includes a' cam 56,. which is fixed'to the'm'astic-fe eding conduitE, and a lever-57 operatively connected to the valve, this lever.havin'gian:end 58 bearing against the cam. When the valve is closed, the end 58 of the lever projectsinto a. recess 59 fashioned in thecam. As'the nozzle D swings in arcounterclockwise direction in Figure 2, the end 58'of the lever 57'rides'out of the recess 59,.an-d the cam will move the valve 55 so as to uncover the outlet opening 54 (see Figure 3"). Upon withdrawing the caulking gun A from themember H, the spring 49"will'. swing the nozzle D-backinto the position illustrated in Figure 2; and a hook won the cam will engage with the lever-end 58, causing the latter tore-enter the=recess1 59, thus closing the valve.

As an important'str'uctural 'detaiLla guide wheel M is secured'to the traction wheel'G by screws 61; (see Figure 4). Spacers 62 are interposed between thesewh'eels soas to maintain themin separated relation with one another; A' gasket washer 62a is interposed between the nozzle D and thewheelG.

engage with a lateral edge-63 of the memberH and A. stop 46 is I It will'b'e apparent that theguidewheel is larger in diameter than the traction wheel so that a peripheral section of the wheel- M will move therealcng, whereby the mastic will 'be'extruded from the nozzle at a predetermined distance from. the edge 63, as will be obvious by reference to Figure 1.

For the purpose of protecting the driven mechanism I and the clutch K, a housing 64 may be removably secured to the conduit E by screws 65, or other suitable fastening means.

Of course the supply of mastic C must be replaced in the tubular handle B from time to time. Accordingly, a filling tube 66 has been provided which extends through the section E of the conduit B so as to communicate with the forward end of the bore 10. Any suitable pump (not shown) may be utilized for forcing the mastic through the tube 66. As the handle is thus filled, the mastic will push the piston F rearwardly. As indicated in Figure 1, a spring-pressed valve 67 automatically closes the tube 66 when the pump is withdrawn therefrom. My copending application, Serial No. 454,563 discloses a pump suitable for this purpose.

Turning now to the modification illustrated in Figures 8 and 9, the same mastic-feed caulking gun A is employed, with the exception that the guide wheel M has been omitted, and a modified, nozzle D has been substituted. Like reference numerals have been applied to corresponding parts of the two embodiments of the gun.

This modified nozzle has an offset portion 68 that is arranged in the plane of the traction wheel G, and it is designed for delivering mastic C through its outlet opening 54a to a groove 69 formed in a building structure H As shown in Figure 9, the traction wheel G may be pressed into the groove 69 so as to guide the gun along the structure H while a ribbon 20a of the mastic is delivered into the groove. Inasmuch as the groove 69 serves as a guide for the traction wheel, no guide wheel is required in this form of the caulking gun.

Summary of operation The operation of the first embodiment of my automatic feed caulking gun A, as disclosed in Figures 1 to 6, inclusive, is summarized briefly as follows:

Assuming that the tubular handle B contains a supply of the mastic C,.and that the operator desires to secure wall boards 21 to the studs H (or other building structure), by ribbons 20 of the mastic (see Figure 7), the operator first moves the mastic-delivering nozzle D against the stud, with the guide wheel M aligned with the lateral edge 63 of the stud (see Figures 1 and 2). Then the gun is pushed toward the stud until the surface 47 of the nozzle contacts with the stud and the traction wheel G contacts the stud. At this time, a peripheral section of the guide wheel M will overlap the stud and the valve 55 will be opened automatically (see Figure 3).

As the gun is advanced along the stud, as suggested by the arrow 28, the traction wheel will be rotated in the direction of the arrow 29. This will cause the drive mechanism J to turn the drum 11; and, through the medium of the cable 12, the piston F will 'be drawn forwardly in the bore of the handle. This will result in extruding a ribbon 20 of the mastic against the stud at a predetermined distance from the lateral edge 63 of the stud. The nozzle will swing against the action of the spring 49, as the gun is advanced, and thus the surface 47 will maintain contact with the stud.

As the piston reaches the forward end of its stroke,

it will push the clutch-operating rod 41 forwardly, re

sulting in disengaging the clutch K. This will permit the driven gear 30 to turn freely on the hollow shaft 31; and thus the cable 12 will not be broken, in the event that the operator should attempt to continue pushing the gun along the stud. At any time that the operator removes the gun from the stud, the nozzle D, will be returned to its normal position (see Figure 2) by the spring 49 and the valve 55 will close automatically.

When filling the groove 69 of the building structure H with mastic, the modified nozzle D is utilized (see Figures 8 and 9). Here, the offset mastic-delivering portion 68 of the nozzle will insert ribbon 20a of the mastic into the groove 69, while the traction Wheel G rides along the bottom of this groove, with the walls of the groove serving to guide the forward movement of the caulking gun along the building structure. Otherwise, the operation of this form of the invention is the same as that previously described in connection with the first embodiment.

'I claim:

1. In an automatic feed caulking gun: a tubular handle having a bore adapted to contain a supply of mastic; a mastic-delivering nozzle arranged adjacent to one end of the handle; a mastic-feeding conduit placing the bore of the handle in communication with the nozzle, whereby mastic may be transferred from the bore to the nozzle; a piston mounted in the bore in back of the supply of mastic, and being movable toward the nozzle to advance mastic to the latter; a rotatable drum carried by the handle and having one end of a cable anchored thereto, with the other end of the cable being fastened to the piston; a traction wheel mounted adjacent to the nozzle and rotatable on an axis transverse thereto so as to be engageable with a member against which mastic is to be including means operable for automatically disengag ing the traction wheel when the piston reaches a prede-' termined point at the forward end of its stroke, thereby precluding the breaking of the cable upon further rotation of the traction wheel; said drum disengaging means including a clutch, and a clutch-operating rod arranged in the path of the advancing piston and adapted to be actuated by the piston when the latter reaches a predetermined point in its stroke for disconnecting the drum from the drive mechanism.

2. In an automatic feed caulking gun: a tubular handle having a bore adapted to contain a supply of mastic; a mastic-delivering nozzle arranged adjacent to one end of the handle; a mastic-feeding conduit placing the bore of the handle in communication with the nozzle, whereby mastic may be transferred from the bore to the nozzle; a pistonmounted in the bore in back of the supply of mastic, and being movable toward the nozzle to advance mastic to the latter; a rotatable drum carried by the handle and having one end of a cable anchored thereto, with the other end of the cable being fastened to the piston; a traction wheel mounted adjacent to the nozzle and rotatable on an axis transverse thereto so as to be engageable with a member against which mastic is to be extruded when the gun is used; the wheel being rotatable when the operator moves the handle and advances the wheel along said member in engagement therewith; and a drive mechanism connecting the traction wheel with the drum for turning the latter when the wheel isrotated for winding the cable and moving the piston for forcing mastic out the nozzle; said drive mechanism including means operable for automatically disengaging the drum from the traction wheel when the piston reaches a predetermined point at the forward end of its stroke, thereby precluding the breaking of the cable upon further rotation of the traction wheel; the drum extending transversely across the forward end of the tubular handle and the piston being rotatable about its axis; the cable being guided to the piston in offset relation with respect to the piston axis, whereby the piston will be rotated as the cable is wound. on the drum from one end of the drum toward its opposite end so 'as to permit the cable portion between the drum and the piston to lie in a -transversely movingplanethat extends substantially at right angles tothe drum axis at all times.- I

3. In anautomatic feed caulking gun': a tubular handle having a bore adapted to contain a supply' of mastic; a masticrd'elivering-no'z-zle arranged: adjacent to one end of the handle;-a mastic-feeding conduit placingthe bore of the handle-in communication with the' noz-zle, whereby mastic may be transferred from'the bore t'o th'e nozzle; a piston mounted in the bore in tiatives the supply of mastic, and being movable toward the nozzle to advance mastic to the latter;- a rotatable drum carried by the handle and having one end ofa cablean choredthereto, with the other end of the cable' being fastened to the piston; a traction wheel mounted adjacent' to the nozzle and rotatable on an axistransverse thereto so as to be engageable with a member against which mastic is to he extruded when the gun' is-usedi the wheel being rotatable whenthe operator moves. the handle andadvances the wheel along said member in engagement therewith; a drive mechanism connecting the" traction" wheel with the drum for turning thelatter when the wheel is rotated for winding the cable and moving the piston for forcing mastic out the nozzle; said drive mechanism includingmeans operable for automatically disengaging the drum' from the traction wheel when the piston reaches a predetermined point at the forward end of its stroke, thereby precluding the breaking of the cable upon further rotation of the traction wheel;

and a guide spaced laterally from the gun and being carried'thereby; the guide beingengageable with an edge of said member and movable therealong' as the gun is moved, whereby the mastic will be extruded from the nozzle onto said member at a predetermined distance from said edge.

4. In an automatic feed ca'ulking'gun: a tubularhandlej having a bore adapted to contain a supply of mastic; a

mastic-delivering nozzle arranged adjacent to one end'of',

the handle; a mastic-feeding conduit placing the bore of the handlein' communication with the nozzle, whereby mastic may betransferre'd from the bore to the nozzle; a piston mounted in the bore in back of thesupply' of mastic, andbeing movable toward the nozzle to advance mastic to the latter; a rotatable drum earriedby the handle and having one end of'a cable anchoredther eto, with the other end of the cable being fastened to the piston; a traction wheel mounted-adjacent to the nozzle" and rotatable on an axis transverse thereto-so as tolbe" engageable with a'rnember" against which mastic is to be extruded when the gun is'u's'ed; the Wheel being. ro tatable when' the operator moves the handle and advances the wheel' along said" member in engagement therewith; and a drive rnechanism connecting the traction wheel with the drum for turning the latter when the wheel is rotated" for winding the cable a'ndmo'ving' the piston'for forcing mastic out the-nozzle'; said drive mechanism including" having a bore adapted. to contain a' supply'ofmastic;"a-

mastic-delivering nozzle swingable about'an axis trans verse to the handle and arranged adjacent to'one end o'f the handle; a-mastic-feeding conduitv placing 'the bore of the handlein communication with the Lnozzle; wherebymastic may betransferredfrom the bore to the n'ozzlegia piston mounted in the bore in back of the supply of mastic, and being movable toward the; nozzle to advance mastic to thelatter; means operable to advance thepiston and-including atraction wheel whose axis coincides with the nozzle axis; and" yielding means urging the nozzle to a predeer'mined-inopera'ive position, the outer end of the-nozzle projecting beyond the traction wheel peripheryj the nozzle having an outlet end provided with a surface arrang'ed to slidably abut the surfaceof a member against which the traction wheel bears and on which the mastic is to'be extruded when the gun is used; the

noz'zlebeing swingable by the yielding means as the handle is moved' along saidmember, so as tocause the nozzle to keep in contact with said surface on thememberat all times and permit the handle to assume different angular-positions with respect to said surface during the-- entire caulking operation.

6. Thecombination as set forth in claim 5; and in which a valve is mounted in the nozzle to control the outflow of mastic therefrom; and a valve-actuating device is connected to-the' handle and disposed adjacent to the nozzle and" operatively' connected to the valve for automatically opening itwhen the nozzle is brought into contactwith the surface on the member and is swung intooperative position; the valve-actuating device automatically closing the valve when the nozzle is removed from themember and said yielding means returns the nozzle to inoperative position.

7. In' an automatic feed caulking gun: a tubular handle having a'bore adapted to contain asupply of mastic; a

maStic deliVerin'g nozzle carried by the handle and'commu'nicating with -the handle interior at one end thereof so as to receive mastic therefrom; said nozzle being swingab-le 'about-an axis that'extends transverse to the handle and having an outletdesignedto lay a mastic-ribbon on a surface paralleling the axis when the nozzle contacts the surface and is moved thereover; a piston mount ed in the handle bore for forcing mastic from the bore and out through the nozzle; a traction wheel rotatable about the nozzle axis and supported by the gun; the radius of said wheel being less thanthe distance the nozzle outlet is removed from the axis; whereby the nozzle is adapted to contact with the same surface contacted by the traction wheel; piston-moving means operatively connecting the wheel with the piston so that a movement of the gun handle for causing the wheel to travel over the surface,

will-rotate the wheel and advance the piston for causing" V it-to feed mastic through the nozzle and onto the same surface for depositing a mastic ribbon thereon; and spring means for yieldingly'swinging the nozzle about its axis for causingit to contact with the surface regardless of the angular position of the handle'with respect to the surfaceysaid spring means swinging the nozzle intoinoperative position when the nozzle is removed from the surface-- 8. The combination as set forth in claim 7; and in which the portion of the nozzle projecting beyond the wheelperiphery has a wall that is always tangent tothe periphery and will ride on the surface contacted by the wheel; the outlet for the nozzle being related to the said nozzle wall for laying a mastic ribbonof the desired thickness and shape on the surface asthe traction wheel moves thereover.

9. The combination-as set forth in claim 7; and in which the-nozzle has-an oifset portion with an outlet Whose center liesin a-plane coinciding with the plane of the traction wheel; said spring means being adapted to swing the nozzle for keeping the outlet of the otfset portion in contact with a surface paralleling the surface contac'ted by the traction wheel.

References Cited in the'fileof this patent UNITED STATES PATENTS 2323;963' Ames July 13, 194 2,413,634 Atnes Jan. 7, 1947 2,815,142 A Ames Dec. 3, 1957 

